Remove powerpc32 strncmp comments about bounded pointers

[Ryan S. Arnold]

On Mon, Mar 4, 2013 at 5:54 PM, Joseph S. Myers <joseph@codesourcery.com> wrote:
> When I was removing bounded pointers relics from powerpc32 code I missed
> some comments in three versions of strncmp saying that the bounded
> pointers support there (now all removed) is broken.  I've committed as
> obvious this patch to remove those comments.

Thanks!